


Just a Fantasy

by sakuranomi808



Category: Supernatural
Genre: Car Sex, Fantasizing, Hand Jobs, M/M, Masturbation, blowjob
Language: English
Status: Completed
Published: 2020-12-03
Updated: 2020-12-04
Packaged: 2021-03-09 23:53:29
Rating: Explicit
Warnings: Underage
Chapters: 2
Words: 2,893
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27855434
Author URL: https://archiveofourown.org/users/sakuranomi808/pseuds/sakuranomi808
Summary: Written for SPN kink meme prompt: Dean, masturbation, fantasy, taboo -- I just want Dean beating off his huge dick while fantasying about something really taboo. He could be fantasying about fucking his little brother, or other small children, or about fucking an animal, or about rape/snuff. Whatever taboos works for you go with it. I just prefer top!Dean in all scenarios
Relationships: Dean Winchester/Sam Winchester
Comments: 12
Kudos: 244





	1. Chapter 1

**Author's Note:**

> Posted this anonymously at first, but figured I should just let my kink flag fly and post it here \o/

When Sam turned twelve, Dad had inexplicably started renting two adjoining motel rooms instead of one, and in doing so -- something about Sam had changed. Maybe it was because Sam was always butting heads with Dad, so not having to be under his watchful eye all the time made Sammy a little less stressed out, a little more carefree. 

It was all fine by Dean, who was mostly just grateful to finally have a bed of his own -- he was sixteen years old after all, and didn’t exactly need his little brother elbowing him in the face every other second while he was trying to get some sleep. But nowadays, instead of coming out of the shower with a towel wrapped around his waist, Sam would just casually walk into the room completely naked and rummage around in his duffel for some clean clothes. It had happened a handful of times now, enough times for it to not be a coincidence. 

Dean tried his best to ignore it, and was failing miserably. 

Sam was wearing just a pair of tight white briefs now, towel draped over his shoulder, and he was bending over to examine the air conditioning unit mounted to the window a couple of feet above the carpeted floor. He huffed in frustration as he fiddled with the switches and knobs, the lean muscles in his back flexing as he struggled with it. 

“Dean, this thing’s broken again,” Sam whined. 

“I’ll take a look at it,” Dean replied absently, craning his neck from his vantage point on the bed to take in the sight of Sam’s ass. 

Sam was beautiful -- perfect in Dean’s eyes -- balanced precariously on the cusp of childhood and adulthood. Other adolescents would be awkward at this age, but not Sam. Sam had had an early growth spurt and was almost as tall as Dean, with lean strong muscles beginning to form in his chest, back and arms. 

“I’m so hot,” Sam complained. 

“No kiddin’,” Dean muttered under his breath as he tossed his magazine down on the bed and crossed the room to where his brother was standing. Trying his damnedest to ignore the heat literally radiating off of Sam’s body, Dean crouched down and examined the stupid AC unit. He was absolutely not looking at Sammy’s crotch, even when Sam stood up straight and the outline of his half-hard dick trapped in his little-boy briefs was inches away from Dean’s face. Dean was already rock hard in his jeans and damn it -- it really was sweltering hot in this room -- he could not get the AC to work. 

“Sorry, kiddo,” Dean said. “D’ya want me to go see if anyone’s at the front desk?” 

“It’s okay,” Sam replied, all wide earnest eyes holding Dean’s gaze as the older brother rose to his feet. “I’m pretty tired from staying up late studying last night. I think I’ll just hit the sack.”

Dean forced a smile and nod, pressing a chaste kiss to Sam’s forehead before shutting off the lights and settling down on his own bed. Dean liked to think he was pretty strong willed, but no matter how hard he tried, he could not will his erection away. He tried thinking about cutting heads off vamps, and staking evil creatures through the heart, but somehow -- maybe he was just that fucked up in the head -- that made his dick even harder. 

Seven agonizing minutes later, Sam’s breathing evened out and Dean knew his little brother was asleep. He ventured a glance over at the other bed and had to bite back a sigh. Sam was gorgeous: the soft blue light of the moon peeked through the part in the curtains, casting a sliver of light over his soft, full lips, drawing angled shadows on his face where his lashes fluttered against his cheekbones. He had fallen asleep on top of the covers wearing just his briefs, and was curled up slightly on his side, one arm curled under his head and the other draped over his torso. 

Dean quietly slipped into the bathroom and closed the door, practically tearing at the button and zipper on his jeans to free his aching cock from his boxer briefs. He hiked his t-shirt up under his armpits and sighed with relief as he began to jerk himself off hard and fast, chasing after his release. He was almost certain that he was just horny and needed to get off. 

It had absolutely nothing to do with Sam.

Just as he was about to come, Dean stopped abruptly, squeezing hard just under the swollen head to stave off his orgasm. Who was he kidding? It had everything to do with Sam -- his stupidly gorgeous little brother who was always making up some excuse to prance around nude in front of Dean, to brush up against him when they were sitting side-by-side in a booth having dinner with Dad. 

Was he imagining it, or was Sam totally trying to seduce him? 

Dean huffed in frustration as he sat down on the edge of the bathtub and took in a few deep breaths, feeling utterly conflicted and just as horny as he had been a few minutes ago. His gaze dropped down to where his jeans were still undone, his briefs still tucked under the swell of his balls. His cock was so hard that it was starting to hurt, the head an angry shade of dark red and pre-come pulsing from the swollen slit. Dean smoothed the slippery-wet liquid down over his shaft and pumped a couple of times, imagining that Sam was on his knees between Dean’s legs, sucking his dick. 

A fresh rush of heated blood shot straight down to Dean’s cock at the filthy imagery -- of Sam’s soft lips stretched wide around his shaft, nostrils flaring as he struggled to breathe, working Dean’s length in and out of his mouth. Sam probably wouldn’t be able to fit all of it in there, so maybe he’d let some saliva drip down and use his hand in tandem along with his mouth. Dean shut his own eyes and spit into one hand, working both of his clenched fists now over his stiff flesh. 

Dean knew for a fact that Sam was a virgin and he couldn’t keep his mind from wandering to the thought of fucking his brother’s tight little asshole. He wouldn’t hurt him of course; Dean would spend hours if he needed to, working Sam open one finger at a time, licking over Sam’s twitching hole until he was begging for it. Dean slowed his pace for a moment, imagining what it would feel like to sink slowly into Sam’s warm, tight channel, pushing in deeper and deeper until his whole length was buried inside his baby brother’s ass. 

The thought of it was as thrilling as it was terrifying, and that excited Dean even more. He picked up the pace again, thrusting his hips up into his clenched fist as his other hand dropped down to palm over his balls. He thought about how Sam would look while he was getting fucked -- his mouth open slightly as he struggled to catch his breath, his eyes squeezed shut in pleasure, perspiration beading on his forehead and chest. 

Dean bit back a groan as he thought about kissing Sam -- just smashing their lips together as they fucked, dipping his tongue into his brother’s sweet little mouth as he pounded into Sam’s ass with his cock. Oddly enough, that thought is what pushed Dean over the edge, his orgasm tearing abruptly through him, punching the air from his lungs as the first spurt of his come shot halfway across the bathroom floor. “Oh fuck, Sammy…” he breathed, realizing only after he’d spoken his brother’s name that he’d actually said that out loud. He was too far gone to stop now though, and continued to jerk himself off, sure and strong as spurt after spurt of his release painted the tile beneath his feet. 

The only thing Dean could hear now was his own heartbeat thundering in his ears, all of his senses a little too keen as he gradually came down from his climax. He blew out a shaky breath through pursed lips and reached over to grab some tissues to clean up. His whole body was still thrumming with pleasure and he felt so relieved that he couldn’t even find it in himself to feel bad about what he’d been fantasizing about. After all, it was just a fantasy -- he wasn’t hurting anyone. 

Dean opened the door and quietly slipped back into the bedroom, stopping abruptly when he saw that his brother was awake, just lying there looking silently up at Dean through his lashes.

“Hey Sammy,” Dean murmured, suddenly grateful for the darkness. How much had Sam heard through the closed door? “Everything okay?”

“Y-yeah,” Sam stammered. Even in just the light of the moon, Dean could see his brother’s cheeks flush red, and he knew that Sam had heard everything. A tiny smile tugged at Sam’s lips as he said, “Everything’s great.”


	2. Give and Take

**Summary for the Chapter:**

> Continuation of this story based on another kink meme prompt: Dean and Sam fooling around in the backseat of the impala. At the drive in movies, while John is driving, at lover’s lane, wherever. Take it as far as you want but I prefer bottom Sam.

Whatever this thing was between them -- this dirty, wonderful, dangerous thing -- it was going to be the death of him, Dean just knew it. And Sam was either oblivious to it, or he was getting off on the fact that Dad had almost caught them several times now, and would probably murder Dean without hesitation if he ever did. 

The last time had been the closest call yet: Dean was laid out on his bed, jeans pushed down to his thighs with Sam nestled between his legs, languidly sucking on his cock. Sam seemed almost mesmerized by it, pausing every so often to drag his fingertips over the veins along the shaft, studying it so closely that it almost seemed like he was trying to memorize its every detail. They’d been at it for a while already, but Sam really loved sucking Dean’s dick and Dean was not about to deny his brother what he wanted. He was absently twisting his fingers through Sam’s silky hair when they both heard it -- the roar of the Impala’s engine as Dad pulled into the motel parking lot. 

Dean had tried to push Sam off, but Sam -- bratty little brother that he was -- just doubled down on his efforts and started sucking Dean in earnest, curling his fist tight around Dean’s erection and working it expertly in tandem with his mouth. Dean’s eyes had slammed shut and he’d come down Sam’s throat in ten seconds flat, giving them just enough time to get themselves sorted out before Dad peeked his head in through the door that joined his room with theirs to let them know he was back. 

And right now: Sam was doing an awful job of pretending to nod off to sleep as they roared down the highway, leaving the town they’d called “home” for the last three months behind them. The last bit of light from the setting sun had just dispersed into a black, starless sky when Dad glanced at them in the rearview mirror, his gaze lingering for a moment before turning his attention back to the road. 

“We’ll be there in a few hours,” Dad said. “You boys go ahead and get some sleep if you need to.” 

Dean nodded and mumbled an affirmative response, biting his tongue hard to stop himself from saying anything else as Sam slid across the backseat and sidled up against Dean. He pulled the fleece blanket in his lap up over both of them and glanced at Dean wordlessly, tugging his bottom lip between his teeth as he looked up through his thick fringe of lashes. How someone could look so innocent and so completely filthy at the same time was almost beyond comprehension. 

Dean turned his body so that his back was against the door, and brought one leg up to stretch across the backseat, planting his other foot firmly on the floor. Sam grinned and lay down against Dean’s chest, curling up on his side so that he was completely nestled against the curve of his big brother’s body. Dean pulled the blanket over both of them and closed his eyes, even though the warmth and weight of Sam’s body sent all of his blood rushing straight down to his cock. 

It was just the slightest, almost imperceptible movement, but Sam somehow managed to slip his hand between them to unbutton and unzip Dean’s pants. Dean had to bite back a groan as Sam started to massage and knead his hardening length, knowing exactly how to stroke and squeeze to get Dean fully hard in just a few seconds. This was probably the worst idea either of them had ever had, but Dean couldn’t really think straight anymore with Sam’s thumb flicking over the sensitive bundle of nerves just under the crown, coaxing out a drop of pre-come from the swollen slit. 

Dean licked his lips and fumbled in the darkness, easily finding the waist of Sam’s sweats and slipping one hand under the elastic. His eyes widened and his pulse quickened at the realization that Sam was not wearing any underwear. The fact that his brother had probably planned this little escapade even before they checked out of the motel had Dean even harder than before, if that was even possible. He lowered his gaze and found Sam already looking up at him, a tiny smile tugging at the corners of his mouth as he continued to jerk Dean off, slow and steady now. 

Dad was lost in thought as he coasted down the highway; he always got like this when his mind was on a case he was chasing. He probably didn’t even remember that his boys were in the backseat of the car. Dean was incredibly grateful for that as he began to mimic Sam’s movements, stroking his brother’s perfectly slender cock in his fist, circling his palm over the head on the upstroke every other time, just the way Sam liked it. 

There was just the lightest dusting of wispy brown hair starting to grow at the base of Sam’s cock but his balls were still completely smooth and hairless, which Dean loved more than he cared to admit. He paused his efforts on Sam’s dick for a moment to roll the sacs in his palm, one and then the other, gently nudging the tips of his fingers further back until he brushed over Sam’s asshole. 

The younger boy sucked in a startled gasp and both of them froze, eyes darting to the driver’s seat to check if Dad had heard them. Thankfully, his eyes were still glued to the dark road in front of them. Heart thundering madly behind his ribs, Dean caught his brother’s gaze and held it steady as he ventured back again, more confident this time as he pressed the pads of his fingers against the clenched opening. He could feel the muscles in Sam’s body pulsing and flexing as he tried to force himself to relax.

They hadn’t ever done this before, but Dean had sure thought about it enough -- about what it would be like to kiss and lick Sam down there until he relaxed enough to let Dean dip one finger in, and then another, and another until he worked Sam open enough to take his cock. He was afraid Sam wouldn’t want to, but judging by the tiny gasps and mewls coming from his brother’s lips as Dean massaged his hole, maybe Sam was open to the idea, after all. 

But not now. 

Right now, both of them were hard as nails and needed release as much as they needed the air in their lungs. Dean just wished he could kiss Sam while they jerked each other off, but even Dad wasn’t oblivious enough not to notice that. Instead Dean just gently maneuvered his brother’s body so that they were laid out nearly flat on the backseat chest-to-chest, Sam somewhat awkwardly straddling Dean’s leg. But this way, he could feel Sam’s heart hammering against his own, feel his brother’s exhales flowing over his lips as he inhaled -- back and forth, give and take, just like it had always been between them. 

Dean could sense that both of them were getting close judging by the fact that they both leaked pre-come like crazy when they were turned on. He doubled his efforts, stroking and squeezing over Sam’s shaft hard and fast, again and again until Sam’s body seized and jerked and, without warning, he spilled over Dean’s clenched fist. Dean did his best to work his brother through it, even though he was coming now too, his orgasm tearing through him, streaks of warm, slippery-wet come spurting between their sweaty stomachs over and over again. 

This was definitely up there at the top of the Worst Ideas list, but Dean really didn’t care as the warm, post-orgasmic haze washed over him and he carefully slipped his hand out of Sam’s sweats. They were both a mess and would need to figure out a way to inconspicuously make it to the bathroom at the next rest stop, but they’d worry about that later. 

For now, Dean just closed his eyes and gave his brother a gentle squeeze as Sam’s body relaxed fully against his.


End file.
